A relative double commutant theorem for hereditary sub-C*-algebras

We prove a double commutant theorem for hereditary subalgebras of a large class of C*-algebras, partially resolving a problem posed by Pedersen[8]. Double commutant theorems originated with von Neumann, whose seminal result evolved into an entire field now called von Neumann algebra theory. Voiculescu proved a C*-algebraic double commutant theorem for separable subalgebras of the Calkin algebra. We prove a similar result for hereditary subalgebras which holds for arbitrary corona C*-algebras. (It is not clear how generally Voiculescu's double commutant theorem holds.)

Relationship of physical activity with motor skills, aerobic fitness and body fat in preschool children: a cross-sectional and longitudinal study (Ballabeina).

Adiposity, low aerobic fitness and low levels of activity are all associated with clustered cardiovascular disease risk in children and their high prevalence represents a major public health concern. The aim of this study is to investigate the relationship of objectively measured physical activity (PA) with motor skills (agility and balance), aerobic fitness and %body fat in young children. This study is a cross-sectional and longitudinal analyses using mixed linear models. Longitudinal data were adjusted for baseline outcome parameters. In all, 217 healthy preschool children (age 4-6 years, 48% boys) participated in this study. PA (accelerometers), agility (obstacle course), dynamic balance (balance beam), aerobic fitness (20-m shuttle run) and %body fat (bioelectric impedance) at baseline and 9 months later. PA was positively associated with both motor skills and aerobic fitness at baseline as well as with their longitudinal changes. Specifically, only vigorous, but not total or moderate PA, was related to changes in aerobic fitness. Higher PA was associated with less %body fat at baseline, but not with its change. Conversely, baseline motor skills, aerobic fitness or %body fat were not related to changes in PA. In young children, baseline PA was associated with improvements in motor skills and in aerobic fitness, an important determinant of cardiovascular risk.

Distal dendrites of frog motor neurons: a computer-aided electron microscopic study of cobalt-filled cells.

With the aid of the cobalt labelling technique, frog spinal cord motor neuron dendrites of the subpial dendritic plexus have been identified in serial electron micrographs. Computer reconstructions of various lengths (2.5-9.8 micron) of dendritic segments showed the contours of these dendrites to be highly irregular, and to present many thorn-like projections 0.4-1.8 micron long. Number, size and distribution of synaptic contacts were also determined. Almost half of the synapses occurred at the origins of the thorns and these synapses had the largest contact areas. Only 8 out of 54 synapses analysed were found on thorns and these were the smallest. For the total length of reconstructed dendrites there was, on average, one synapse per 1.2 micron, while 4.4% of the total dendritic surface was covered with synaptic contacts. The functional significance of these distal dendrites and their capacity to influence the soma membrane potential is discussed.

Representation of motor habit in a sequence of repetitive reach and grasp movements performed by macaque monkeys: evidence for a contribution of the dorsolateral prefrontal cortex.

In the context of an autologous cell transplantation study, a unilateral biopsy of cortical tissue was surgically performed from the right dorsolateral prefrontal cortex (dlPFC) in two intact adult macaque monkeys (dlPFC lesioned group), together with the implantation of a chronic chamber providing access to the left motor cortex. Three other monkeys were subjected to the same chronic chamber implantation, but without dlPFC biopsy (control group). All monkeys were initially trained to perform sequential manual dexterity tasks, requiring precision grip. The motor performance and the prehension's sequence (temporal order to grasp pellets from different spatial locations) were analysed for each hand. Following the surgery, transient and moderate deficits of manual dexterity per se occurred in both groups, indicating that they were not due to the dlPFC lesion (most likely related to the recording chamber implantation and/or general anaesthesia/medication). In contrast, changes of motor habit were observed for the sequential order of grasping in the two monkeys with dlPFC lesion only. The changes were more prominent in the monkey subjected to the largest lesion, supporting the notion of a specific effect of the dlPFC lesion on the motor habit of the monkeys. These observations are reminiscent of previous studies using conditional tasks with delay that have proposed a specialization of the dlPFC for visuo-spatial working memory, except that this is in a different context of "free-will", non-conditional manual dexterity task, without a component of working memory.

Fatigue et réduction de la performance motrice chez le sportif, syndrome de surentraînement [Fatigue and reduction in motor performance in sportspeople or overtraining syndrome].

The main goal of training activities is to improve motor performance. After strenuous workouts, it is physiological to experience fatigue, which relieves within two weeks, and then induce an improvement in motor capacities. An overtraining syndrome is diagnosed when fatigue is postponed beyond two weeks, and affects mainly endurance athletes. It is a condition of chronic fatigue, underperformance and an increased vulnerability to infection leading to recurrent infections. The whole observed spectrum of symptoms is physiological, psychological, endocrinogical and immunological. All play a role in the failure to recover. Monitoring of athletes activities helps to prevent the syndrome with days with no sports. Rest, patience and empathy are the only ways of treatment options.

Motor de veu natural per dispositius mòbils

S’ha optimitzat un motor de veu natural per a dispositius mòbils com una PDA o un telèfon mòbil basat en un sistema operatiu Windows. La finalitat d’aquest treball és la d’ajudar a fer més fàcil la utilització d’aquests aparells a gent invident i que pugui acabar sent una donació a la ONCE.

Effect of levodopa on both verbal and motor representations of action in Parkinson's disease: a fMRI study.

Previous studies have demonstrated that non-demented Parkinson's disease (PD) patients have a specific impairment of verb production compared with noun generation. One interpretation of this deficit suggested the influence of striato-frontal dysfunction on action-related verb processing. The aim of our study was to investigate cerebral changes after motor improvement due to dopaminergic medication on the neural circuitry supporting action representation in the brain as mediated by verb generation and motor imagery in PD patients. Functional magnetic resonance imaging on 8 PD patients in "ON" dopaminergic treatment state (DTS) and in "OFF" DTS was used to explore the brain activity during three different tasks: Object Naming (ObjN), Generation of Action Verbs (GenA) in which patients were asked to overtly say an action associated with a picture and mental simulation of action (MSoA) was investigated by asking subjects to mentally simulate an action related to a depicted object. The distribution of brain activities associated with these tasks whatever DTS was very similar to results of previous studies. The results showed that brain activity related to semantics of action is modified by dopaminergic treatment in PD patients. This cerebral reorganisation concerns mainly motor and premotor cortex suggesting an involvement of the putaminal motor loop according to the "motor" theory of verb processing.

Aplicació informàtica per al registre del comportament motor en les situacions pràxiques

Durante los dos años que van desde noviembre de 2005 a noviembre de 2007, en los que se ha llevado a cabo la Beca de colaborador en el ámbito del deporte, tanto en el CAR de Sant Cugat como en el Consell Catala de l’Esport, se han investigado y estudiado las acciones práxicas de un deporte tan popular, pero al mismo tiempo tan desconocido, como es el futbol. El primer año se investigaron las acciones práxicas que finalizaron en gol en la Liga de Fútbol Profesional, Liga Española, temporada 2005-2006. Dichas investigaciones sirvieron como una primera toma de contacto en relación a este tipo de estudios y sirvieron también para elaborar unas primeras aplicaciones informáticas que nos permitieran el registro de dichas acciones para su posterior análisis. Durante el segundo año, se trabajó en la confección de una aplicación informática que reflejara y permitiera el registro de las acciones práxicas del portero de futbol durante un partido de competición. Así mismo, durante este segundo año también se elaboraron y publicaron dos artículos científicos relacionados con las investigaciones llevadas a cabo en el primer año de Beca. La finalidad y propósito de toda esta serie de investigaciones y trabajos ha sido conocer en profundidad el deporte en cuestión para poder plantear nuevas metodologías y planteamientos de entrenamiento basadas en la competición, que nos permitan mejorar el rendimiento en el deporte investigado. 

Mutations in the colony stimulating factor 1 receptor (CSF1R) gene cause hereditary diffuse leukoencephalopathy with spheroids.

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is an autosomal-dominant central nervous system white-matter disease with variable clinical presentations, including personality and behavioral changes, dementia, depression, parkinsonism, seizures and other phenotypes. We combined genome-wide linkage analysis with exome sequencing and identified 14 different mutations affecting the tyrosine kinase domain of the colony stimulating factor 1 receptor (encoded by CSF1R) in 14 families with HDLS. In one kindred, we confirmed the de novo occurrence of the mutation. Follow-up sequencing identified an additional CSF1R mutation in an individual diagnosed with corticobasal syndrome. In vitro, CSF-1 stimulation resulted in rapid autophosphorylation of selected tyrosine residues in the kinase domain of wild-type but not mutant CSF1R, suggesting that HDLS may result from partial loss of CSF1R function. As CSF1R is a crucial mediator of microglial proliferation and differentiation in the brain, our findings suggest an important role for microglial dysfunction in HDLS pathogenesis.

Aging and motor programming: differential effects according to the selection of action

There are controversial reports about the effect of aging on movement preparation, and it is unclear to which extent cognitive and/or motor related cerebral processes may be affected. This study examines the age effects on electro-cortical oscillatory patterns during various motor programming tasks, in order to assess potential differences according to the mode of action selection. Twenty elderly (EP, 60-84 years) and 20 young (YP, 20-29 years) participants with normal cognition underwent 3 pre-cued response tasks (S1-S2 paradigm). S1 carried either complete information on response side (Full; stimulus-driven motor preparation), no information (None; general motor alertness), or required free response side selection (Free; internally-driven motor preparation). Electroencephalogram (EEG) was recorded using 64 surface electrodes. Alpha (8-12 Hz) desynchronization (ERD)/synchronization (ERS) and motor-related amplitude asymmetries (MRAA) were analyzed during the S1-S2 interval. Reaction times (RTs) to S2 were slower in EP than YP, and in None than in the other 2 tasks. There was an Age x Task interaction due to increased RTs in Free compared to Full in EP only. Central bilateral and midline activation (alpha ERD) was smaller in EP than YP in None. In Full just before S2, readiness to move was reflected by posterior midline inhibition (alpha ERS) in both groups. In Free, such inhibition was present only in YP. Moreover, MRAA showed motor activity lateralization in both groups in Full, but only in YP in Free. The results indicate reduced recruitment of motor regions for motor alertness in the elderly. They further show less efficient cerebral processes subtending free selection of movement in elders, suggesting reduced capacity for internally-driven action with age.

Are glutamate and lactate increases ubiquitous to physiological activation? A (1)H functional MR spectroscopy study during motor activation in human brain at 7Tesla.

Recent studies at high field (7Tesla) have reported small metabolite changes, in particular lactate and glutamate (below 0.3μmol/g) during visual stimulation. These studies have been limited to the visual cortex because of its high energy metabolism and good magnetic resonance spectroscopy (MRS) sensitivity using surface coil. The aim of this study was to extend functional MRS (fMRS) to investigate for the first time the metabolite changes during motor activation at 7T. Small but sustained increases in lactate (0.17μmol/g±0.05μmol/g, p<0.001) and glutamate (0.17μmol/g±0.09μmol/g, p<0.005) were detected during motor activation followed by a return to the baseline after the end of activation. The present study demonstrates that increases in lactate and glutamate during motor stimulation are small, but similar to those observed during visual stimulation. From the observed glutamate and lactate increase, we inferred that these metabolite changes may be a general manifestation of the increased neuronal activity. In addition, we propose that the measured metabolite concentration increases imply an increase in ΔCMRO2 that is transiently below that of ΔCMRGlc during the first 1 to 2min of the stimulation.

Ophtalmologie. Thérapie génique des rétinopathies héréditaires: premiers résultats [Gene therapy for hereditary eye diseases: where are we?]

Les résultats préliminaires de trois essais cliniques de thérapie génique d'une forme agressive de rétinite pigmentaire (l'amaurose congénitale de Leber) ont prouvé que le traitement des maladies dégénératives de la rétine par transfert de gène peut être sûr et efficace pour rétablir une fonction visuelle. Il faudra encore attendre les résultats à long terme de ces études pour que soit définitivement validée cette approche thérapeutique. Dans l'intervalle, il importe de se préparer à son introduction en ophtalmologie de façon à la rendre accessible à nos malades. Pratiquement cela revient à promouvoir: 1) le recrutement; 2) la caractérisation du phénotype et du génotype des sujets atteints et 3) la constitution d'un registre des rétinopathies héréditaires. Recently, preliminary results of three clinical gene therapy trials for early onset retinitis pigmentosa--Leber congenital amaurosis--suggested that treating this degenerative retinal disease by gene transfection can be safe and efficient to restore a visual function. The definitive validation of this therapeutic approach depends on the long-term results. The forthcoming availability of gene therapy in ophthalmology prompts the implementation: of 1) recruitment, 2) phenotyping and genotyping of affected patients, 3) and creation of a hereditary retinopathy registry.

Effects of unilateral motor cortex lesion on ipsilesional hand's reach and grasp performance in monkeys: relationship with recovery in the contralesional hand.

Manual dexterity, a prerogative of primates, is under the control of the corticospinal (CS) tract. Because 90-95% of CS axons decussate, it is assumed that this control is exerted essentially on the contralateral hand. Consistently, unilateral lesion of the hand representation in the motor cortex is followed by a complete loss of dexterity of the contralesional hand. During the months following lesion, spontaneous recovery of manual dexterity takes place to a highly variable extent across subjects, although largely incomplete. In the present study, we tested the hypothesis that after a significant postlesion period, manual performance in the ipsilesional hand is correlated with the extent of functional recovery in the contralesional hand. To this aim, ten adult macaque monkeys were subjected to permanent unilateral motor cortex lesion. Monkeys' manual performance was assessed for each hand during several months postlesion, using our standard behavioral test (modified Brinkman board task) that provides a quantitative measure of reach and grasp ability. The ipsilesional hand's performance was found to be significantly enhanced over the long term (100-300 days postlesion) in six of ten monkeys, with the six exhibiting the best, though incomplete, recovery of the contralesional hand. There was a statistically significant correlation (r = 0.932; P < 0.001) between performance in the ipsilesional hand after significant postlesion period and the extent of recovery of the contralesional hand. This observation is interpreted in terms of different possible mechanisms of recovery, dependent on the recruitment of motor areas in the lesioned and/or intact hemispheres.

Relationship of aerobic fitness and motor skills with memory and attention in preschoolers (Ballabeina): a cross-sectional and longitudinal study.

BACKGROUND: The debate about a possible relationship between aerobic fitness and motor skills with cognitive development in children has recently re-emerged, because of the decrease in children's aerobic fitness and the concomitant pressure of schools to enhance cognitive performance. As the literature in young children is scarce, we examined the cross-sectional and longitudinal relationship of aerobic fitness and motor skills with spatial working memory and attention in preschool children. METHODS: Data from 245 ethnically diverse preschool children (mean age: 5.2 (0.6) years, girls: 49.4%) analyzed at baseline and 9 months later. Assessments included aerobic fitness (20 m shuttle run) and motor skills with agility (obstacle course) and dynamic balance (balance beam). Cognitive parameters included spatial working memory (IDS) and attention (KHV-VK). All analyses were adjusted for age, sex, BMI, migration status, parental education, native language and linguistic region. Longitudinal analyses were additionally adjusted for the respective baseline value. RESULTS: In the cross-sectional analysis, aerobic fitness was associated with better attention (r=0.16, p=0.03). A shorter time in the agility test was independently associated with a better performance both in working memory (r=-0.17, p=0.01) and in attention (r=-0.20, p=0.01). In the longitudinal analyses, baseline aerobic fitness was independently related to improvements in attention (r=0.16, p=0.03), while baseline dynamic balance was associated with improvements in working memory (r=0.15, p=0.04). CONCLUSIONS: In young children, higher baseline aerobic fitness and motor skills were related to a better spatial working memory and/or attention at baseline, and to some extent also to their future improvements over the following 9 months. TRIAL REGISTRATION: clinicaltrials.gov NCT00674544.